Animal Repro

• Male Reproductive Tract


  • Scrotum
  • Testis
  • Epididymis
  • Ductus (vas) deferens
  • Accessory sex glands
  • Penis
• Scrotum


  Cools testes so sperm doesn't denature
• Testis


  Produce sperm and sex hormones (testosterone)
• Epididymis


  Mature and store sperm
• Ductus (vas) deferens


  Transport sperm
• Accessory sex glands


  Produce seminal plasma
• Penis


  Copulatory organ
• Position of Testes


  • Scrotal (primates, domestic mammals)
  • Extrascrotally (birds, marine mammals, elephant)
• Female Reproductive Tract


  • Ovary
  • Uterine tube (oviduct)
  • Uterus
  • Cervix
  • Vagina and vestibule
• Ovary


  Produce oocytes and sex hormones
• Uterine tube (oviduct)


  Transports the oocyte
• Uterus


  Supports development of the embryo and fetus
• Cervix


  Protects uterine environment
• Vagina and vestibule


  Copulatory organ, expels the fetus
• Hormones of Reproduction


  • Gonadotrophins (Follicle stimulating hormone, Luteinizing hormone)
  • Steroid hormones (Oestrogens, Progesterone, Testosterone)
• Gonadotrophins


  Controlled by gonadotrophin releasing hormone (GnRH) which is released by hypothalamus
• Steroid hormones


  Produced by ovary, testes, placenta
• Ovaries and follicular growth


  • Primordial follicles
  • Primary follicles
  • Secondary follicles
  • Tertiary (antral) follicles
• Testes and Spermatogenesis


  • Seminiferous tubule lumen
  • Sertoli cells
  • Developing germ cells
  • Blood vessels
  • Connective tissue
  • Lymphatics
  • Leydig cells
• The Sperm Journey


  1. Sertoli cells

  2. Seminiferous tubules

  3. Rete tubules

  4. Efferent ducts

  5. Epididymis

  6. Ductus deferens

  7. Pelvic urethra

  8. Penile urethra
• Pregnancy recognition


  Embryo signals presence to mother, differs between species
• Gestation


  Increased HR, BP in female system
• Parturition


  1. Fetus signals readiness

  2. Placental secretions change from P4 to E2

  3. Prostaglandin F2α secretion increases

  4. Oxytocin levels increase

  5. Labour induced

  6. Foetus turns into neonate and had to detach itself from the umbilical cord

  7. Foetus expelled
• Reproduction


  The natural process among organisms by which new individuals are generated and the species perpetuated
• Phases of Animal life


  • Vegetative
  • Reproductive
• Strategies of reproduction


  • R type species
  • K type species
• Methods of gamete transfer


  • Spermatophore
  • Quasi copulation
  • True Copulation
• Copulation


  Duration usually short especially in prey animals, frequency depends on species, individual, availability of females, health and stamina
• Reproductive strategies


  • Monogamy
  • Promiscuity
  • Polygamy (Polyandry, Polygyny)
• Puberty


  The period or age at which a person is first capable of sexual reproduction of offspring
• Seasonality


  The state or quality of being seasonal or dependent on the seasons
• Senescence


  Growing old; aging
• Maintenance of a population involves both vegetative and reproductive phases
• Reproduction involves


  • Courtship
  • Copulation
  • Gestation
  • Parturition
  • Offspring rearing
• Must not neglect vegetative phase in reproductive management
• Reproduction Varies with


  • Age
  • Season
  • Cycle stage
  • Sexual Determination
• Fetal period


  In both sexes, reproductive potential is determined to some extent by the time of birth
• Infancy


  Vegetative period - mostly controlled by metabolic hormones, Reproductive hormone activity dominated by negative feedback of sex steroids on pituitary
• Immediately preceding puberty


  Pituitary contains Gn's but they are not secreted in large quantities, Peaks of Gn's gradually increase closer to puberty, Follicles develop and secrete low levels of E2 but ovulation does not occur, Low level spermatogenesis may occur
• Puberty


  Animal gains the ability to produce offspring, Requires physiological, physical and behavioural maturation, Not a dramatic event; can take months - years